New York Times:  “Legal marijuana . . . businesses are conducted almost entirely in cash because it is exceedingly difficult for them to open and maintain bank accounts, and thus accept credit cards.  The . . . drug remains illegal under federal law. The Controlled Substances Act, enacted in 1970 classifies marijuana as a Schedule I drug, the most dangerous category, which also includes heroin, LSD and ecstasy.  As a result, banks, including state-chartered ones, are reluctant to provide traditional services to marijuana businesses. They fear that federal regulators and law enforcement authorities might punish them, with measures like large fines, for violating prohibitions on money-laundering, among other federal laws and regulations.  “Banking is the most urgent issue facing the legal cannabis industry today,” said Aaron Smith, executive director of the National Cannabis Industry Association in Washington, D.C.”